1. Field of the Invention
This invention relates to tamper indicating closures for application to container necks. The tamper indicating feature indicates that closure has been previously removed, or an attempt has been made to remove it from the container. More particularly, this invention relates to a tamper indicating closure in which a tamper indicating band depends from the bottom of the cap skirt by spaced frangible webs. When the cap has been threaded onto the container neck, the tamper indicating band is retained by a bead on the container neck. When the closure cap is unthreaded from the container neck, the tamper indicating band is restrained against axial movement by the container neck bead causing fracture of the frangible webs and separation of the band from the cap. In an alternative embodiment, a tear strip is interposed between the cap skirt and the tamper indicating band with frangible webs between the cap skirt and the tear strip and between the tear strip and the tamper indicating band. In order to remove the cap, the tear strip is first unwound and removed leaving the tamper indicating band on the container and allowing the cap to be removed by unthreading.
2. Description of the Related Art
In presently available tamper indicating band closures, the band is provided with an inwardly directed bead which coacts with an outwardly directed bead or flange on the container neck. In the process of threading the cap onto the container neck, the bead on the tamper indicating band snaps over the bead on the container neck. In the unthreading process, the band is restrained against axial motion by coaction between the bead on the tamper indicating band and the container bead so that the frangible webs between the bottom of the cap skirt and the top of the tamper indicating band are fractured. The inwardly directed bead on the tamper indicating band requires a complex mold design to remove the formed closure from the mold core.